Physics Questions

Q 51 When electric dipole is placed in uniform electric field its two charges experience equal and opposite forces which cancel each other and hence net force on electric dipole in uniform electric field is zero However these forces are not collinear so they give rise to some torque on the dipole Since net force on electric dipole in uniform electric field is zero so no work is done in moving the electric dipole in uniform electric field However some work is done in rotating the dipole against the torque acting on it An electric dipole consists of two opposite charges each of magnitude 1 0 C separated by a distance of 2 0 cm The dipole is placed in an external field of 105 N C 1 The maximum torque on the dipole is a 0 2 x 10 3 Nm b 1 x 10 3 Nm c 6 10 3 Nm d 4 x 10 3 Nm

Q10 The uniform ring of mass m and radius R is free to rotate abo fixed axis AB Find the maximum angular speed attained by the ri when it is slightly disturbed from the position shown The ring is kept a uniform magnetic field Bo A B C D 161 B m 161 B m 161B Am 4 InB H m R

Electrostatic and Capacitance Example 2 78 Figure shows a combination of twelve capacitors each of capacitance C forming a cube Find the equivalent capacitance of the combination i between the diagonally opposite corners A and B of the cube ii and between the diagonally opposite corners A and D of a face of the cube A B C D

41 An A C source is connected to a resistive circuit Which of the following statements is true A Current leads the voltage in phase B Current lags the voltage in phase C Current and voltage are in same phase D Either A or B depending on the value of resistance

20 resistance is connected in series of a cell of emf 2 2 volt The voltmeter across the resistance reads 2 V thus internal resistance of the cell is A B 0 2 0 0 10 10 40

D variable resistor Q53 Why inductance of toroid is more than the inductance of a solenoid having same number of turns core of same material and similar size A Core is endless hence there no leakage of flux B Resistance of wire is less hence magnitude of current flow is more G Number of turns per unit length is more D Both A and B

Correct true statement regarding IGBT Has HIGH INPUT IMPEDANCE AS MOSFET AND HAS High ON STATE POWER LOSS AS IN BJT h O Has HIGH INPUT IMPEDANCE AS MOSFET AND HAS LOW ON STATE POWER LOSS AS IN BJT O Has Low INPUT IMPEDANCE AS MOSFET AND HAS LOW ON STATE POWER LOSS AS IN BJT Has Low INPUT IMPEDANCE AS MOSFET AND HAS High ON STATE POWER LOSS AS IN BJT

2 5 of 90 Two cars are travelling in the same direction with a velocity of 60 kmph They are separated by a distance of 5 km A truck moving in opposite direction meets the two cars in a time interval of 3 minute The velocity of the truck is in kmph 20 30 You marked

A fresh dry cell of 1 5 volt and two resistors of 10 k each are connected in series An analog voltmeter measures a voltage of 0 5 volt across each of the resistors A 100 F capacitor is fully charged using the same source The same voltmeter is now used to measure the voltage across it The initial value of the current and the time in which the voltmeter reading falls to 0 5 volt are respectively A 60 A 11s B 120 A 15s C 150 A 15s D 150 A 1 1 s

air bubble in sphere having 4 cm diameter appears 1 cm from surface nearest to eye when looked along diameter If all stance of bubble from refracting surface is A B D 1 2 cm 3 2 cm 2 8 cm 1 6 cm

c vector is translated parall d vector is rotated Minimum number of unequal coplanar vectors required whose vector sum can be equal to zero is a two b four c three d any of the above roduces the same effect as

In the following part of a circuit i 5 A dl 3 As 12 2A 4 A s Find VA VB dt 2H2V 3V 3H 39 Awwwwwwwww B 20 al www 40 4 V 4H T JEE Foundations Jucational Services Limited

P 0 0 d generated due to various charge distributions and the dependence of E on d is found to be different for different charge distributions List l contains different relations between E and d List Il describes different electric charge distributions along with their locations Match the functions in List I with the related charge distributions in List II ut ciru za gch farg P 0 0 d 92 443 fu ld a duz Ea fa f a 3d fazut fg Ma fa 2 1 d qeu f a f a du fra 14 1 1 ah fu mu faa Ma Aya d fazut ww f 1 38 11 f a 3nde faazo y lac I List I E is independent P of d E mc Q Ex R E x S E 8 List II f 11 A point charge Q at the origin Harguz ku ych farg 3aT Q A small dipole with point charges Q at 0 0 1 and Q at 0 0 1 Take 21 d 2 0 0 1 0 0 1 21 d An infinite line charge coincident with the x axis with uniform linear charge 3 density A X ya ygaga Two infinite wires carrying uniform linear charge density parallel to the x axis The one along y 0 z has a charge density I and the one along y 0 z has a charge 4 density 1 Take 2 d z yuma tu fat gy at 313 d az Ma y 0 z det 0 z 3Jf I CH i ch 3d cd 2 d har A P 5 Q3 4 R 1 S 2 Infinite plane charge coincident with the xy plane with uniform surface 5 charge density qat y6893 you de aard Wall G rd 1 4 S 2 B P 5 Q 3 R Correct Answer Your Answer C P 5 Q 3 R 1 2 S 4 D P 4 Q 2 3 R 1 S 5 1

In figure shown car A is travelling due north and car B is traveling due east They collide and stick to each other Here 1 2 3 4 shows possible direction of motion of cars Which is most likely B 1 2 2 4 W

1 7 10 A clock hung on a wall has marks instead of numerals on its dial On the adjoining wall there is a plane mirror and the image of the clock in the mirror indicates the time 7 40 Then the time on the clock is Question Type Single Correct Type 2 4 20 English 3 5 40 Review Q

8 Calculate the magnetic moment of a thin wire with a current I 0 8A wound tightly on half a tore The diameter of the cross section of the tore is equal to d 5 0 cm the number of turns is N 500 in Am

Assertion Mass is a measure of inertia of the body in linear motion Reason Greater the mass greater is the force required to change its state of rest or motion a Both assertion and reason are true and reason is the correct explanation of assertion b Both assertion and reason are true but reason is not the correct explanation of assertion c Assertion is true but reason is false Both Assertion and Reason are false

2 moles of He and 2 moles of O2 are mixed with each other 100R R universal gas constant amount of heat energy is supplied to the gas sample through different processes which are given by expression in List and List Il contains rise in temperature in different processes as given in List l Choose the correct option Symbols given have their usual meanings 2 H 2 0 tg 2 fhul vildl137 f27 f27U P Q mu af zerf 1 ad f geu c aya Al AA 347 444 44 List 1 R S A B C D dp dT dP dV dT dV P T 1 P 2 V P Pressure ra ut mu Afaa 7 u thai c 100R R Hidd tu fu T V 2 3 4 1 a f 1 3 1 zffa fa fHa uxo P 5 Q P 3 Q p Density a 1 List 11 Zero 2 25 K 3 25 K P 1 Q 1 Q 5 R 1 S 3 1 4 25 K 6 5 R 1 S 3 5 2 K 4 5 R 2 S 2 P 3 Q 5 R 1 S 2 Correct Answer

In Young s double slit interference experiment the distance between slits and screen is made 1 6 times initial value by keeping all other parameters same Final band width will be times initial value CO2 O 4 8 O 1 6 O 0 625 O 3 2

which is accelerated downward Suppose a boy is enjoying a ride on a merry go round which is moving with a constant speed of 10 ms 1 It implies that the boy is a at rest b moving with no acceleration moving with uniform velocity c in accelerated motion Assertion Mass is a measure of inertia of the body in linear motion

29 resistance is connected in series of a cell of emf 2 2 volt The voltmeter across the resistance reads 2 V thus internal r the cell is A B D 0 292 0 192 192 Mark 452

Figure shows two blocks A and B are connected through pulley and spring system Block A on a frictionless surface has a mass of 2 Kg Block B suspended by cables has a mass of 3 Kg The spring has a stiffness of k 500 N m and an unstretched length of 400 mm the system is released from rest in the position shown x 800 mm The speed of the block A rounded off to the nearest higher integer in m s when x 0 mm is g 10 m s 600 mm www K 500 N m 3kg B

34 35 36 37 38 39 40 41 42 43 A zener diode having breakdown voltage equal to 10V is used in a voltage regulator circuit shown in figure The current flowing through the diode is 1 10 mA 2 5 mA 3 Question Type Single Correct Type 15 mA 20002 ww 20 mA ISV OV English Review www 1612

9 Two small metal spheres having equal charge and mass are suspended from some point on the ceiling of a damp room with silk threads of equal length Let center to center distance between sphere be x x 1 1 is length of silk thread Due to ionization of medium charge leaks off from each sphere and they keep on coming closer to each other at a constant rate Let their approach velocity v varies as vox 1 2 If mass of each sphere is m then the rate at which charge varies with dq N 2 mg respect to time is 1x1 Find the value of N 1

A man running along a straight road with a uniform velocity u ui feels that the rain is falling vertically downwards along If he doubles his speed he finds that rain is coming at an angle 8 with the vertical The velocity of the rain with respect to the ground is A ui u tan 0 B ui u C u i tane tane D u i tane i

External Work in displacing a Piston A piston can freely move inside a horizontal cylinder closed from both ends Initially the piston separates the inside space of cylinder in two equal parts each of volume V which are filled with an ideal gas at same pressure Po If temperature of gas in two parts is equal and kept constant find the work required to be done in increasing the volume of one part of gas n times compared to the other part by slowly displacing the piston

32 33 34 35 36 37 38 39 40 41 42 English Review Q Which of the following is correct for avalanche breakdown Question Type Single Correct Type 1 Tunneling effect 2 Inter field emission 3 High doping 4 Wider depletion region

A ring of radius r is spun about its axis with an angular velocity in a horizontal plane A uniform magnetic field of magnitude B exists in the region in vertical direction The emf induced in the ring is Zero 1 2 Br Brzo

A Floating Cylinder in Water A thin walled cylinder of mass m height h cross sectional area S is filled with a gas and floats with a part of cylinder in water As a result of the leakage of water from the bottom of cylinder the depth of submerged part has increased by Ah Calculate the initial pressure of gas in cylinder Take atmospheric pressure Po and constant temperature

1 E E 3Eb 2 Ea 3Eb 3 Ea E 3Eb 35 4 Ea 3E E 0 36 37 38 Atomic binding energy of elements A and B are Ea and Eb respectively Three atoms of B form one atom of A In this fusion process E energy is released the relation between Ea E and E Question Type Single Correct Type English 39 38 39 40 Review Q

A platform is moving with velocity V m s in x direction A man starts moving on the platform with velocity 2V in x direction After reaching the right end he returns ba to the initial point In the whole journey his speed is remain constant and equal to 2 Now match the columns below COLUMN 1 1 What is the speed of the man with respect to earth while going in x direction 2 What is the speed of the man with respect to earth while returning back 3 What is the displacement of the particle with respect to earth 4 What is the displacement of the man with respect to platform 5 Find time at which its displacement with respect to earth will be maximum 2V A V D L G L 2V COLUMN 11 B 2V E 2L H L V C 3V F Zero

A man of mass m has fallen into a ditch of width d Two of his friends are slowly pulling him out using a light rope and two fixed pulleys as shown in the figure Both the friends exert forces of equal magnitude F When the man is at a depth h the value of F is mg 4h A 4h C mgd h B mgh d D infinite h d

Match the following two column for a convex lens corresponding to object posi Note O Optical centre F First focus F Second focus Column l Column II p Real A Between O and F B Between F and 2F C Between O and F D Between F and 2F Aa shown in Colum JEE FOLLO s Inverted

A locomotive of mass m starts moving with velocity v a s where a is constant s is distance traversed The total work done by all the forces acting on the locomotive during first t sec 1 4 B ma t 4 A ma 1 4 2 C ma ma 412 D 1ma4t 16 force actin

27 Which of the following is not an application of conservation of linear momentum While firing a bullet the gun must be held tight to the shoulder b When a man jumps from a boat to the shore A rocket explodes on midway from the ground A body suspended from the hook of a spring balanced in a lift which is accelerated downward

A large concave mirror with a radius of curvature of 0 5 m is placed on a horizontal plate We pour a small amount of water into the mirror and place on it a plano convex lens with a radius of curvature of 1 0 m whose plane side just covers the water Then we place a point light source above this set up at a height of 0 3 m The distance in metres between the object and the final image formed will be x 90 Find x given that the refractive index of water is 4 3 and the refractive index of glass is 1 50

Sand is being dropped from stationary hopper at the rate of 5 kg s on to a conveyor belt moving with a constant speed of 2 m s What is the power delivered by the motor drawing the belt A 10 watts C 30 watts B 20 watts D 40 watts du

PASSAGE Consider a resistance of 2002 an inductance of 0 2 H and a capacitance of 100 F are connected in series across 220 V 50 Hz mains Determine the following Choose the correct option Marks 2 Calculate voltage drop across inductance OPTIONS 384 51 V

13 In a parallel plate capacitor the region between the plates is filled by a dielectric slab The capacitor is connected to a cell and the slab is taken out Some charge is drawn from the cell Some charge is returned to the cell c The potential difference across the capacitor is reduced d No work is done by an external agent in taking the slab out

4 A body of mass 20 kg starts from rest at the top of a hill of height 50 m and moves down the rough curved track If its speed at the bottom is 30ms the work done by friction is g 10ms 1 10 000 T 2 1000 50 m 2 1001 4 10 1

Digital Classroom NEETUO Physics 17 18 19 20 21 22 23 24 25 26 10 20 0401 20 resistance is connected in series of a cell of emf 2 2 volt The voltmeter across the resistance reads 2 V thus internal resistance of the cell is Question Type Single Correct Type 20 10 101 13 3 10 02 56 47 40

6 A particle starts from rest accelerates at 2 ms 2 for 10 s and then goes for constant speed for 30 s and then decelerates till it stops after next What is the distance travelled 2 at 4 ms by it a 750 m b 800 m c 700 m d 850 m

A block of mass 0 1 kg attached to a spring of spring constant 400 N m is pulled horizontally from x 0 to x 10 mm Find the work done by spring force 1 2 x 10 2 J 2 2 x 10 6 J 3 3 x 106 J 4 4 x 10 J

In the adjoining figure if the block starts of moving from rest work done by the frictional force from t 1 sto t 2s is A 60 J C 180 J B 120 J D 240 J 10 kg of a spring 37 0 5

5 A point charge Q is moved along a circular path around another fixed point charge The work done is zero only if Q returns to its starting point only if the two charges have the same magnitude only if the two charges have the same magnitude and opposite signs in all cases

a CD b DE c AB d BC 10 Which of the following statements is not correct a Whenever the amount of magnetic flux linked with a circuit change an emf is induced in circuit b The induced emf lasts so long as the change in magnetic flux continues c The direction of induced emf is given by Lenz s law d Lenz s law is a consequence of the law of conservation of momentum

string 5 beats per second is heard If tension in the string is slightly increased then beats with the same tuning fork become 3 beats per second The frequency of stretched wire before increasing the tension is Frequency of tuning fork is 256 Hz 1 261 Hz 2 256 Hz 3 251 Hz 4 259 Hz

A particle moves along the x axis so that at time t 0 its position is given by x t 2t3 312 36t 50 What is the total distance travelled by the particle over the time interval 0 t 5 90 145 195 50

7 An ammeter and a voltmeter are joined in series to a cell Their readings are A and V respectively If a resistance is now joined in parallel with the voltmeter both A and V will increase both A and V will decrease A will decrease V will increase A will increase V will decrease

Two objects of the same mass slide down on two different smooth inclined plane of same height but of different angles When they reach the bottom then 1 and 1 are the impulses of the weights of the first and the second object during the motion P and P2 are the powers developed by the weights of the first and the second objects sina2 sin 1 C sina 12 sin 2 A D R 2R 4 1 B 063 P sina P2 sina Hey